The invention relates to a short message routing method and apparatus in a public land mobile network providing both packet data service and circuit switched service.
Short message service in general is widely known in mobile telecommunication networks. A special type of such a network, called GPRS (General Packet Radio Service), has been specified by ETSI (European Telecommunication Standardization Institute) in the GSM specification GSM 03.60, Feb. 27, 1997, Version 1.1. Both mobile terminated and mobile originated short message transfer between the various nodes in the GPRS communication system, are described in this GSM specification.
The specification does not give the network operator and/or the subscriber or end-user any flexibility in controlling how the short messages are routed through the network.
This will be described below with reference to FIGS. 1-4 on the appended drawings.
FIG. 1 schematically illustrates an embodiment of part of an existing public land mobile network providing both packet data service and circuit switched service in accordance with the invention,
FIG. 2 illustrates a known successful mobile terminating transfer via packet service of a short message in the network in FIG. 1,
FIG. 3 illustrates a known unsuccessful mobile terminating transfer via packet service of a short message in the network in FIG. 1, and
FIG. 4 illustrates a known successful mobile originating transfer via packet service of a short message in the network in FIG. 1.
FIG. 1 schematically illustrates an embodiment of part of an existing public land mobile network providing both packet data service and circuit switched service. The illustrated network includes a home location register HLR, a mobile switching center/visitors location register MSC/VLR, a base station system BSS, a short message services gateway mobile switching center SMS-GMSC combined with a short message services inter working mobile switching center SMS-IWMSC, a short message service center SM-SC, a serving general packet radio service support node SGSN, and a gateway general packet radio service support node GGSN. In FIG. 1, a single mobile station MS is also shown.
An example of a successful short message service (SMS) to the mobile station (MS) in the network in FIG. 1, i.e. a successful mobile terminating transfer of a short message (SM), will be described with reference to FIG. 2.
In step 1, the short message service center (SM-SC) determines that it shall send a SMS to a MS and forwards the SMS to the SMS-GMSC. In step (2), the SMS-GMSC examines the address of the MS and sends a xe2x80x9csend routing info (SRI) for SMxe2x80x9d message to the HLR.
In step 3, the HLR returns a xe2x80x9cSRI for SM acknowledgementxe2x80x9d message to the SMS-GMSC. In the transfer illustrated in FIG. 2, this message is supposed to contain both the SGSN address and the MSC address of the MS assuming that the HLR has stored these addresses after previous GPRS and GSM routing area/location updating.
In accordance with this known transfer, the SMS is always sent first via GPRS.
Thus, in step (4), the SM-GMSC forwards the SMS to the SGSN.
In step (5), the SGSN transfers the SMS to the MS.
In case of a successful short message transfer to the MS, in step (6), SGSN returns a report to the SMS-GMSC indicating successful delivery of the SMS.
In step (7), the SMS-GMSC returns a report to the SM-SC indicating successful delivery of the SMS.
FIG. 3 illustrates an example of an unsuccessful SMS transfer to a MS. Steps (1)-(4) in FIG. 3 are identical to steps (1)-(4) in FIG. 2.
In step (5) in FIG. 3, however, the SGSN attempts to transfer the SMS to the MS but fails. This may occur i.e., if the MS is not attached to GPRS or when the radio channel conditions are bad.
In step (6) in FIG. 3, the SGSN sets the mobile station not reachable flag MNRF and returns a failure report to SMS-GMSC indicating unsuccessful delivery of the SMS.
In step (7) in FIG. 3, the SMS-GMSC selects the alternative, lower preference route for the short message using the MSC address received in step (3) as described in connection with FIG. 2. Thus, the SMS is forwarded to the MSC/VLR. In step (8), the MSC-VLR attempts to transfer the SMS to the MS by means of existing GSM procedures, but in this example, it is supposed that the attempt fails.
In step (9) in FIG. 3, the MSC/VLR sets the mobile station not reachable flag MNRF and returns a failure report to the SMS-GMSC indicating unsuccessful delivery of the SMS.
In step (10) in FIG. 3, the SMS-GMSC sends a xe2x80x9cshort message delivery report statusxe2x80x9d message to the HLR.
In step (11), the HLR updates its message waiting indication fields and returns a xe2x80x9cshort message delivery report status acknowledgementxe2x80x9d message to the SMS-GMSC.
In step (12), finally, the SMS-GMSC returns a failure report to the SM-SC indicating unsuccessful delivery of the SMS.
The two transfer procedures described above in connection with FIGS. 2 and 3 do not provide any flexibility in that the SMS is always sent first via GPRS and in that the operator of the network and/or the end-user of the MS, i.e. the user of the terminating MS, is not allowed to control how the SMS should be routed through the network.
In FIG. 4, an example of a known successful SMS transfer from a MS to a SM-SC is illustrated.
In step (1) in FIG. 4, the SM is transferred from the MS to the SGSN via the BSS.
In step (2) in FIG. 4, the SGSN forwards the SMS to the SMS-IWMSC.
In step (3), the SMS is supposed to be successfully transferred to the SC.
In step (4), a report of the successful transfer is sent from the SC to the SMS-IWMSC.
In step (5), the SMS-IWMSC reports the successful transfer to the SGSN, and in step (6), the successful transfer is reported by the SGSN to the MS.
Also in mobile originating transfers of SMSs, the SMSs are always sent first over GPRS, thus, no flexibility is provided for mobile originating SMS transfer since the network operator and/or the end-user of the MS are not allowed to control how the mobile originating SMS should be routed through the network.
This means that for each mobile terminating or mobile originating SMS transfer, the GPRS will always have preference over the circuit switch (CS) service, i.e. the SMS is sent first over GPRS, and the end-user will, first, always be charged according to GPRS fares. Only if the mobile terminated SMS transfer fails with GPRS, the end-user will be charged according to the CS service fares.
As stated above, presently, the SMS will always be sent first over GPRS. As a consequence, the network operator has no way to re-route the SMS over CS in case of GPRS capacity problems, congestion problems, network problems etc. A SMS transfer has to fail over GPRS before the SMS will be sent to CS. Thus, signalling capacity will be used for nothing. Furthermore, the end-user will always be charged first according to the GPRS fares and will be charged according to the CS fares only if the SMS fails over GPRS and succeeds over CS. The operator does not offer any different charges based on the path used for the delivery of the SM.
The object of the invention is, therefore, to provide flexibility to the network by enabling the operator and/or the end-user to control how the short messages are routed through the network.
This is attained by the method, according to the invention, of routing a short message with high or low priority from a service center to a mobile station in a public land mobile network providing both packet data service and circuit switched service, in that a choice is made, in advance, as to whether the short message should be received by the mobile station either via a specific one of the services or via any of the services. Based upon said choice in step, the priority of the short message sent from the service center, and an indication of whether the mobile station is reachable via one, both or none of the services, a route via one of the services, a route via both services or no route at all is selected. If a route via one of the services is selected, the short message is routed in accordance with the selected route. If a route via both services is selected, the route via the service having a higher preference than the other service is selected, and the short message is routed in accordance with the route via said service having the higher preference. If the routing of the short message to the mobile station is unsuccessful via the route via said service having the higher preference,the short message is routed in accordance with the route via said other service having lower preference.
This object is also attained by the apparatus, according to the invention, for routing a short message with high or low priority from a service center to a mobile station in a public land mobile network providing both packet data service and circuit switched service, in that means are provided to enable a choice, in advance, as to whether the short message should be received by the mobile station either via a specific one of the services or via any of the services. Means are also provided to select, on the basis of said choice, the priority of the short message sent from the service center, and an indication of whether the mobile station is reachable via one, both or none of the services, a route via one of the services, a route via both services or no route at all. Means are provided to route the short message in accordance with the selected route, if a route via one of the services is selected. Means are provided to, on the one hand, select the route via the service having a higher preference than the other service, and, on the other hand, route the short message in accordance with the route via said service having the higher preference, if a route via both services is selected. Means are provided to route the short message in accordance with the route via said other service having lower preference if the routing of the short message to the mobile station is unsuccessful via the route via the service having the higher preference.
Hereby, a flexibility for both the network operator and the end-user will be obtained.